JP4658761B2 - Damper material for seismic isolation devices - Google Patents

Description

  The present invention relates to a damper material used in a seismic isolation device that is installed between a building and its foundation to absorb the shock and vibration of an earthquake.

  Seismic isolation devices that are installed between a building and its foundation to protect the building by absorbing earthquake shocks and vibrations generally have laminated rubber (hard plates such as steel plates and viscoelastic properties such as rubber) It consists mainly of a base-isolated rubber (isolator) laminated with a soft plate and a damper. The seismic isolation rubber of the seismic isolation device uses the softness of the shear rigidity of the rubber and the large deformation capability to create a slip between the foundation and the building in the horizontal direction, thereby reducing the seismic force. The damper also absorbs energy during vibration and imparts damping performance to the seismic isolation structure, thereby suppressing excessive relative displacement between the building and the ground that occurs during the earthquake.

  Conventionally, lead is mainly used as a material constituting the damper of such a seismic isolation device. An asphalt thermoplastic material (see, for example, Patent Document 1) has also been proposed.

  However, lead that is currently mainly used as a damper material for seismic isolation devices is greatly restricted in manufacturing and design from the viewpoint of environmental problems. Moreover, since the problem of the disposal at the time of discarding a seismic isolation apparatus is also anticipated in the future, the damper material for seismic isolation apparatuses which replaces lead is calculated | required.

On the other hand, the asphalt-based thermoplastic material has a remarkably large temperature dependency of its performance, and is effective for indoor use where the temperature is adjusted. However, stable performance cannot be exhibited in an environment exposed to outside air such as the lower part of a building.
Japanese Patent No. 2998788

  An object of the present invention is to solve the problems of the conventional damper material for a seismic isolation device. That is, an object of the present invention is to provide a damper material for a seismic isolation device that has an excellent vibration damping effect and is effective as a lead substitute damper material.

  As a result of intensive studies to solve the above-described conventional problems, the present inventors have considered using a resin material as a damper material in place of lead. However, it has been found that the original properties of the resin may be lost in the damper material formed by melting and molding the resin material. This is probably because the damper material formed by melting the resin is different from the case of producing a thin material such as a sheet or a film, and the performance is changed because the cooling rate is slow. Accordingly, the present inventors have focused on a compression molding method capable of molding a damper material without melting, and have arrived at the present invention as described below.

  That is, the present invention comprises a composition containing at least two types of resins having different melting points, and is at a temperature higher than the melting point of the low melting point resin having the lowest melting point among the resins, and has the highest melting point among the resins. A damper material for a seismic isolation device, which is compression-molded at a temperature lower than the melting point of a high melting point resin.

  The damper material for a seismic isolation device of the present invention preferably includes at least one of the following first to fourth aspects.

(1) The first aspect is an aspect in which the high melting point resin is a polyethylene terephthalate resin and the low melting point resin is a polyethylene resin.
(2) A 2nd aspect is an aspect containing resin powder of low melting | fusing point rather than the said high melting point resin.
(3) In the third aspect, the resin powder is at least one selected from the group consisting of ultrahigh molecular weight polyethylene, low density polyethylene, linear polyethylene, ethylene vinyl acetate, ethylene ethyl acrylate, and polypropylene. It is.
(4) A 4th aspect is an aspect whose compounding quantity of the said resin powder is 0.01-5 mass%.

  ADVANTAGE OF THE INVENTION According to this invention, it is excellent in the damping effect and can provide the damper material for seismic isolation devices effective as a damper material of lead substitution.

  The damper material for the seismic isolation device of the present invention comprises a composition containing at least two types of resins having different melting points, and is at a temperature higher than the melting point of the low melting point resin having the lowest melting point among the resins, and among the resins It is compression molded at a temperature lower than the melting point of the high melting point resin having the highest melting point. By compression molding in such a temperature range, the original characteristics of the resin can be maintained, unlike the case of injection molding that is molded in a molten state. Therefore, it is excellent in handleability as a lead substitute damper material, and can exhibit an excellent vibration damping effect.

  The conditions of compression molding at the time of molding are preferably as follows. That is, the mold temperature is required to be lower than the melting temperature of the high melting point resin among the resin materials to be used, but is preferably 120 to 250 ° C, more preferably 150 to 250 ° C. If the melting point is higher than the melting point of the high melting point resin, melting occurs and it is difficult to maintain the original characteristics of the resin.

  The applied pressure is preferably 1 to 100 MPa, and more preferably 5 to 80 MPa. If it is less than 1 MPa, it may be impossible to mold into a desired shape. If it exceeds 100 MPa, the molding apparatus becomes large, which is not realistic.

  Unlike the case where it is molded by melting, the damper material for a seismic isolation device molded by compression molding as described above is in a state where resin particles are in pressure contact with each other. That is, grain boundaries exist in the damper material for the seismic isolation device.

  When the damper material for a seismic isolation device of the present invention is rod-shaped, the axial length is preferably 50 to 1000 mm, and more preferably 100 to 800 mm. Moreover, it is preferable that a diameter is 20-600 mm, and it is more preferable that it is 50-500 mm.

  High melting point resins used as resin materials include polyethylene terephthalate (PET), polyamide (nylon), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN), polycarbonate (PC), polyvinyl chloride (PVC), poly Tetrafluoroethylene (PTFE) etc. are mentioned. Examples of the low melting point resin include polyethylene (PE), ethylene vinyl acetate (EVA), polypropylene (PP), polyvinyl acetate (PVAc), and ethylene ethyl acrylate (EEA).

  Especially, it is preferable to use a polyethylene terephthalate resin as a high melting point resin and to use a polyethylene resin as a low melting point resin. By using such a resin, high ductility can be expressed. Moreover, in the case of this combination, it is preferable that the compounding quantity of a polyethylene resin shall be 3-120 mass parts with respect to 100 mass parts of polyethylene terephthalate resins. By setting it as 3-120 mass parts, it can be set as resin which expresses the high ductility which made polyethylene terephthalate the sea phase. Furthermore, the melting point of the resin can be measured using a DSC (differential thermal analyzer) at a heating rate of 10 ° C./min.

  Moreover, you may contain a binder as needed. Specifically, at least one powder selected from the group consisting of ultra high molecular weight polyethylene, low density polyethylene, linear polyethylene, ethylene vinyl acetate, ethylene ethyl acrylate and polypropylene is preferable. The binder is preferably contained in the damper material for a seismic isolation device of the present invention in an amount of 0.01 to 5% by mass, and more preferably 0.1 to 3% by mass.

  Hereinafter, a damper using the damper material for a seismic isolation device of the present invention will be described with reference to the drawings.

  First, the damper material for a seismic isolation device of the present invention can be used by being sandwiched between hard materials. For example, it is a usage method as a restraint type damping material or a damping steel plate, but a more effective and effective usage method is to sandwich the damper material for a seismic isolation device of the present invention between hard materials and at the time of shear deformation It is a method of using the energy absorption capacity of

  As shown in FIG. 1, the center part of the laminated structure 6A of the hard material 2 and the general rubber 9 is cut out, and a rod-like damper material for a seismic isolation device is used as the damper material 1 for the seismic isolation device of the present invention in this portion. It can be effectively used as a seismic isolation device 20 that is filled and has flanges 7 and 8 attached to the top and bottom. This seismic isolation device 20 can be disposed between a building and a foundation using a seismic isolation rubber formed by alternately laminating general rubber and hard material.

  The hard material 2 is not particularly limited, and for example, metal, ceramics, glass, FRP, plastics, polyurethane, high hardness rubber, wood, rock, paper, leather and the like can be used.

  FIG. 1 is only an application example of the damper material for a seismic isolation device of the present invention, and the present invention is not limited to any form of seismic isolation as long as it uses the energy absorption capability at the time of shear deformation. The present invention can be effectively applied to an apparatus.

  The damper using the damper material of the present invention may be filled with a pellet (powder) according to the size of the seismic isolation device, or may be filled with an integral rod-shaped resin that is melted and molded. The gap may be filled with pellets (powder) and molded.

  Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples. The materials used in the following examples and comparative examples are as follows.

[Example 1]
(Sample preparation)
Asshine # 5 (manufactured by Mirai Kasei Co., Ltd.) was used as the resin material, compression molding was performed for 30 minutes at a mold temperature of 230 ° C. and a pressure of 3.5 ton. Then, it air-cooled to room temperature (25 degreeC), and produced the pellet (damper material for seismic isolation devices). The shape of the sample was a cylindrical shape with a diameter of 45 mm and an axial length of 75 mm. In addition, the pressure display increased with time compared with the initial stage of pressurization due to the thermal expansion of the resin. Further, during air cooling, the pressure display decreased with time due to the shrinkage of the resin.

(Sample resilience test)
The prepared pellets were mounted in the center hole of the laminate shown in FIG. 1, and a restoring force test was performed. The laminated structure 6A used had an outer diameter of 225 mm, an inner diameter of 45 mm, the number of rubber layers of general rubber was 25, and the thickness of each rubber layer was 1.8 mm. The sample filling factor was 104%. The frequency was 0.3 Hz and the shear strain was 100%. The results are shown in FIG.

  From the results shown in FIG. 2, it was confirmed that a large damping force was obtained and the hysteresis curve was stable, so that it was effective as a damper material.

[Comparative Example 1]
A sample having the same shape as the sample of Example 1 was produced by extrusion molding with Asshine # 5 (manufactured by Mirai Kasei Co., Ltd.) as the resin material in a molten state.

  When the restoring force test of the produced sample was performed under the same conditions as in Example 1, the rod was broken and a large damping force was not obtained. Compared with the pellet of Example 1, it was inferior in practical use.

It is sectional drawing which shows an example of the seismic isolation apparatus using the damper material of this invention. It is a figure which shows the result of the restoring force test (The relationship between a displacement amount and a load) of the pellet of an Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Damper material 2 ... Hard material 6A ... Laminated structure 7, 8 ... Flange 9 ... General rubber 20 ... Seismic isolation device

Claims (5)

  A composition containing at least two types of resins having different melting points, a temperature higher than the melting point of the low melting point resin having the lowest melting point among the resins, and the high melting point resin having the highest melting point among the resins. A damper material for a seismic isolation device, which is compression-molded at a temperature lower than the melting point.   The damper material for a seismic isolation device according to claim 1, wherein the high melting point resin is a polyethylene terephthalate resin, and the low melting point resin is a polyethylene resin.   The damper material for a seismic isolation device according to claim 1 or 2, comprising a resin powder having a melting point lower than that of the high melting point resin.   The resin powder is at least one selected from the group consisting of ultra high molecular weight polyethylene, low density polyethylene, linear polyethylene, ethylene vinyl acetate, ethylene ethyl acrylate, and polypropylene. The damper material for a seismic isolation device according to any one of the above.   A damper material for a seismic isolation device, wherein the amount of the resin powder is 0.01 to 5% by mass.

Images